LITTLE ROCK, Ark. (AP) - Republican legislators who had resisted expanding Medicaid in Arkansas say they're encouraged by a new plan that would allow funds from the federal-state program to purchase private insurance for the newly eligible, but say they need more details on how such a system would work.

The announcement last week that the Obama administration had given Arkansas permission to pursue the plan as an alternative to expanding Medicaid eligibility alters a debate that legislators had said would be the top issue of this legislative session. But state officials and legislators say the idea still has hurdles to face in a majority-Republican Legislature that has generally opposed a straight-up expansion of Medicaid.

"It really just opened up 100 new questions," said House Public Health Committee Chairman John Burris, R-Harrison.

Under the proposal, low-income citizens - those who make up to 138 percent of the poverty line, which amounts to $15,415 per year - would receive private insurance purchased using federal Medicaid dollars. The insurance would be purchased through the exchange created under the federal health care law.

The money would cover the cost of the private insurance premiums, but the state would have the flexibility to impose co-pays and other charges.

The federal government would pay the full cost of the health care expansion for the first three years, after which point the state's portion will begin to gradually increase to 10 percent of the cost.

The concept of putting 215,000 uninsured people on private plans offered through the exchange is appealing to Burris and other Republicans, who say the state's Medicaid program can't handle adding that many people to its rolls.

"You are creating a conservative market-based consumer-friendly health care system as opposed to expanding an already broken Medicaid system that's insolvent and provides lower quality of care," Burris said.

State Human Services officials say administrative costs would drop in the long run, and that adding that many people could help strengthen the state's private insurance market.

"Our philosophy has always been we ought to be doing services if it's not available elsewhere," State DHS Director John Selig said last week. "If the private market can serve these people, we in Medicaid don't have any particular desire to."

Selig said the details the state still needs to work out is how to put 215,000 more people on the exchange, which would more than double the number officials had originally anticipated for the insurance marketplace.

"Our intention overall in doing this is for this as much as possible simply be seamless, that when people go into the private market they look like any other client going into the exchange," Selig said.

The other major question is how the state would set up co-pays that Republicans have long sought as part of any expansion agreement. Selig said recent federal guidelines give Arkansas and other states much more flexibility on co-pays for those making more than 100 percent of the poverty level.

The co-pays would likely be targeted more toward areas that Medicaid thinks recipients should be using less, such as going to the emergency room for non-emergency services, he said.

"I think there's a general feeling that where it's reasonable it makes sense to have cost-sharing at various income levels, particularly for things you want to discourage," Selig said.

Legislators say they want to see in writing what U.S. Health and Human Services Secretary Kathleen Sebelius promised Gov. Mike Beebe and state officials about the new Medicaid approach. The U.S. Department of Health and Human Services hasn't publicly confirmed many of the details that Beebe and DHS have announced about the new approach on expanding health coverage in the state.

"Our goal in working with states has been to be as flexible as possible within the confines of the law," Erin Shields Britt, a spokeswoman for the federal department, said last week. "In her meeting with Governor Beebe, Secretary Sebelius expressed support for ideas from the state that would take advantage of this flexibility and said she was glad to see the state considering an innovative, state-based approach."

Senate Public Health Committee Chairwoman Cecile Bledsoe said she wants to know more.

"What I heard were things that I liked, but I need the details and I feel like we need to handle it possibly in a special session," said Bledsoe, R-Rogers. "This is a very complicated matter, and it's not just a question of do you like what you've heard but how does it all work together?"

Beebe has said he wants legislators to make a decision in the current session.

The other hurdle may be a lack of detail so far on how much the private plan would cost as opposed to regular Medicaid expansion. Selig has said the department expects costs for Medicaid will likely go down since it wouldn't have the administrative costs of adding more people to its rolls, but Beebe has said legislators likely won't see a new dollar figure before they vote on this plan.

Beebe has said a proposed "sunset provision" that would require legislators to re-approve the deal before Arkansas' costs kick in after three years would give the state a track record on the cost of the private plan.

The idea still must win over three-fourths of the House and Senate. Republicans are far from saying they're ready to back on to the proposal, but say they're at least ready to move closer to a potential vote.

"We now have the rules to the game," said Sen. Jonathan Dismang, R-Beebe. "So we get to tailor and see what we can come up with."